The latest medical research on Immunology & Allergy

The research magnet gathers the latest research from around the web, based on your specialty area. Below you will find a sample of some of the most recent articles from reputable medical journals about immunology & allergy gathered by our medical AI research bot.

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Prevalence of hyperventilation in patients with asthma.

J Asthma

Asthma is frequently accompanied by dysfunctional breathing of which hyperventilation has been recognized as a subtype. The prevalence of hyperventilation in stable asthma has been scantily studied using blood gas analysis. Hence, a reliable estimate of its prevalence is lacking. It is unknown whether the Nijmegen Questionnaire (NQ) is a useful screening tool for hyperventilation in asthma. Therefore, the primary aim of this study was to determine the prevalence of hyperventilation in a large sample of patients with asthma in a stable state of disease. Secondary aims were to compare the clinical characteristics between patients with and without hyperventilation, and, to examine the concurrent validity of the NQ to detect hypocapnia in patients with asthma.

A real-world, observational, multicenter study was conducted. Capillary blood gas analysis was performed in adults with a confirmed diagnosis of stable asthma. A subset of patients completed the NQ.

A blood gas analysis was obtained in 1006 patients. In 17% of the patients an acute hyperventilation was found, and in another 23% a chronic hyperventilation was uncovered. Patients with a chronic hyperventilation blood gas were more often female, were younger and had a better spirometric outcomes. The NQ appeared not to correlate with PCO2CONCLUSION: Hyperventilation is common in patients with stable asthma. Chronic hyperventilation is more often found in females of younger age and with the best spirometric outcomes compared to patients without hyperventilation. The NQ is not a suitable screening tool for the presence of hyperventilation in stable asthmatics.

Frailty phenotype is associated with antiretroviral exposure among older persons living with HIV.

Current Opinion in Cell Biology

This multicentre, cross-sectional study was carried out in the South of France to assess the association between frailty phenotype and antiretroviral therapy (ART) in older persons living with HIV (PLWHIV). Sociodemographic and HIV data, geriatric assessment, comorbidities, behavioral and age-related variables and the five frailty markers of Fried were recorded. Exposure to any pharmacological class of ART and all regimens were retrieved from medical records.

The 509 PLWHIV analysed (72.7% male) received a mean of 6.01 ART regimens and 12.5 years exposure to ART. The prevalence of at least one frailty marker [frail and prefrail phenotype (FPFP)] was 66.4%. Duration of exposure to protease inhibitors and reverse transcriptase inhibitors, number of ART regimens and comorbidities, dyslipidaemia, cancer, depression, falls, disability and pain were significantly associated with FPFP by univariate analysis. In logistic regression multivariable analysis, independent predictors for FPFP were a large number of ART regimens, presence of cancer and pain. No significant association was found with HIV-related parameters neither with ART class and duration.

A significant association was found between FPFP and a large number of different ART regimens among older PLWHIV. The burden of cancer and pain in these patients shows the importance of comprehensive care.

High Use of SABAs is Associated with Higher Exacerbation Rate in Dutch Patients with Asthma.

Journal of Asthma and Allergy

Many patients with asthma still have insufficient disease control, despite the availability of effective treatment options. A substantial proportion of patients appear to rely more on short-acting beta2-agonist (SABA) rather than on anti-inflammatory maintenance treatment. The aim of this study was to describe differences in indicators of asthma symptoms and exacerbations among patients using more or less SABA than the guideline-recommended threshold of <3 times/week.

Data from Dutch respondents in the European REcognise Asthma and LInk to Symptoms and Experience (REALISE) survey were used in this post hoc analysis. The survey included asthma patients aged 18-50 years with at least two prescriptions for their asthma in the past two years. SABA use was categorized into two groups: <3 (low-SABA users) or ≥3 (high-SABA users) times in the last week.

Of the 736 asthma patients, 21% did not use SABA and 19% used SABA 1 to 2 times (all low SABA users) and 60% used SABA ≥3 times (high SABA users) in the last week. The majority of high and low SABA users also reported using an ICS-containing treatment. Significant differences were found for all indicators related to exacerbations (p<0.001): high SABA users more frequently used antibiotics and oral steroids, more frequently visited the emergency departments or needed an overnight hospital stay. Indicators of asthma symptoms were not significantly different between both groups.

The majority of a Dutch asthmatic population reported high SABA use and had frequent moderate/severe exacerbations. More effective interventions are needed to change healthcare providers' and patients' behaviours to improve care and reduce SABA (over)use.

Real-World Multicenter Experience with Mepolizumab and Benralizumab in the Treatment of Uncontrolled Severe Eosinophilic Asthma Over 12 Months.

Journal of Asthma and Allergy

Treatment of severe eosinophilic asthma (SEA) has been revolutionized by the development of monoclonal antibodies targeting underlying immunological pathways of eosinophilic asthma. Two of the most frequently used antibodies in clinical practice are mepolizumab, targeting interleukin (IL) 5 and benralizumab, targeting the IL5 receptor alpha. The comparative treatment efficacy of these antibodies remains unclear, particularly regarding long-term outcomes.

In this multicenter, retrospective study, we included 123 patients treated with mepolizumab and 64 patients treated with benralizumab for 12 months at one of three study sites in Germany. Data were collected at baseline and after 6 and 12 months of therapy. Endpoints were changes in pulmonary function (PF), exacerbation rate, oral corticosteroid (OCS) use and dose, asthma control test (ACT) score and fractional exhaled nitric oxide (FeNO) levels.

Both mepolizumab and benralizumab led to significant improvements in PF with an increase in median forced expiratory volume (FEV1) after 12 months from 59% to 74% for mepolizumab and 63% to 72% for benralizumab. Treatment also led to significant improvements in ACT scores after 12 months (mepolizumab: 13 [interquartile range (IQR) 9-17] to 19 [IQR 15-23]; benralizumab: 12 [IQR 9-16] to 22 [IQR 16-25]) as well as a reduction of mean OCS dose (mepolizumab 8 mg [IQR 5-12.5 mg] median prednisolone equivalent at baseline to 5 mg [IQR 3-7.5 mg]; benralizumab 7.5 mg [IQR 5-15 mg] to 5 mg [IQR 2-10 mg]). The exacerbation rates were reduced significantly, irrespective of the treatment. Overall, changes were similar after 6 and 12 months of therapy.

Both mepolizumab and benralizumab are highly effective in the long-term treatment of SEA, with no clinically relevant differences in outcomes after 12 months of therapy. In both groups, improvements were similar after 6 and 12 months of therapy, underlining the feasibility of early treatment evaluation.

Management of Chronic Rhinosinusitis with Nasal Polyposis in the Era of Biologics.

Journal of Asthma and Allergy

Chronic rhinosinusitis with nasal polyposis (CRSwNP) is a phenotypic designation of the broader condition of chronic rhinosinusitis. The advent of targeted biologics has shown promise in targeting different aspects of the inflammatory pathway, yet there remains a lack of consensus on the correct timing and use of these medications. This review seeks to provide a concise update of the available literature on the pathophysiology of CRSwNP, the evolution and cost utility of biologics as it pertains to management of patients with CRSwNP, and evidence for each available biologic and its use in CRSwNP.

There are two biologics with FDA approval for use in CRSwNP: dupilumab and omalizumab. Recent clinical trials of other biologic therapies targeting type 2 inflammatory pathways have also demonstrated efficacy both in symptom scores and nasal polyp reduction. However, studies have questioned the cost utility of these medications compared to other interventions. Furthermore, timing of use with respect to other interventions including surgery remains challenging.

Small-Airway Dysfunction is Involved in the Pathogenesis of Asthma: Evidence from Two Mouse Models.

Journal of Asthma and Allergy

There has been growing evidence of small-airway dysfunction in patients with asthma. Few studies have evaluated the mechanism of small-airway dysfunction in mouse models of asthma.

We explored the correlation between small-airway spirometric variables and large-airway function or inflammation in different endotypes of asthma.

Ovalbumin (OVA) sensitization/challenge was used to produce a type 2 (T2)-high asthma model, and OVA combined with ozone exposure (OVA + ozone) was used for the T2-low asthma model with increased neutrophils. Spirometry, airway responsiveness, cytokine levels in bronchoalveolar lavage fluid (BALF), and pathological analyses of lung slices stained with hematoxylin-eosin, periodic acid-Schiff, and Masson's trichrome stain were all determined. Muc5ac expression in lung tissue was evaluated by the reverse transcription-polymerase chain reaction (RT-PCR), and alpha-smooth muscle actin was measured by immunohistochemistry.

Inflammatory cells infiltrated the lung tissue and inflammatory cytokines were increased in the BALF of both the OVA and OVA + ozone groups, compared with the control group. Peribronchial hypersecretion and collagen deposition were evident in the models. The OVA + ozone group showed greater neutrophilic infiltration and peribronchial smooth muscle proliferation than the OVA group. Large-airway obstruction, small-airway dysfunction, and airway hyperresponsiveness were confirmed in both models. Small-airway functional variables, such as MMEF (mean midexpiratory flow, average flow from 25 to 75% forced vital capacity [FVC]) and FEF50 (forced expiratory flow at 50% of FVC), were positively correlated with large-airway function and had a stronger negative correlation with airway inflammation, mucus secretion, and responsiveness than large-airway function.

Small-airway dysfunction was evident in the two endotypes of asthma and was correlated with severe airway inflammation, mucus hypersecretion, and airway hyperresponsiveness. The small airways may be an important target in asthma treatment, and further research in the role of small-airway variables in the pathogenesis of asthma is warranted.

The Relevance of Small Airway Dysfunction in Asthma with Nocturnal Symptoms.

Journal of Asthma and Allergy

Small airway dysfunction (SAD) is a frequent feature of asthma that has been linked to disease severity and poor symptom control. However, little is known about the role of SAD in nocturnal asthma.

To study the association between the severity of SAD and frequency of nocturnal symptoms compared to conventional lung function testing.

We assessed the frequency of self-reported nocturnal symptoms through the asthma control test. We studied the impact of nocturnal asthma using the Asthma Quality of Life Questionnaire (AQLQ) and the Multidimensional Fatigue Inventory (MFI-20). We assessed the lung function using spirometry, body plethysmography, impulse oscillometry, single and multiple inert gas washout and measured markers of T2-inflammation (blood and sputum eosinophils; fractional exhaled nitric oxide (FeNo)). We stratified the patients according to the presence and frequency of nocturnal asthma.

A total of 166 asthma patients were enrolled in the analysis. Eighty-seven patients (52%) reported to have nocturnal symptoms at least once in the last four weeks. The odds ratio of nocturnal asthma correlated with the severity of all non-spirometric measures of SAD, yet neither with airflow obstruction (FEV1 and FEV/FVC) nor with large airway resistance (R20). Patients with frequent nocturnal asthma (n = 29) had a numerical increase of T2 markers and more severe SAD, as indicated by all non-spirometric measures of SAD (all p-values < 0.05), worse overall asthma control, increased fatigue and reduced quality of life (all p-values < 0.01) compared to patients with infrequent nocturnal asthma (n = 58) or patients without nocturnal asthma (n = 79). We identified 63 patients without airflow obstruction, nearly 43% of them (n = 27) had nocturnal asthma. In this subgroup, only markers of air trapping and ventilation heterogeneity were significantly elevated and correlated with the frequency of nocturnal symptoms: LCI (Spearman's coefficient = -0.42, p < 0.001), RV% (-0.32, p = 0.02).

SAD is closely associated to asthma with nocturnal symptoms. Spirometry might underestimate the broad spectrum of distal lung function impairments in this population of patients.

Pediatric Asthma Situation in Chengdu, China, During the COVID-19 Pandemic: An Observational Study.

Journal of Asthma and Allergy

To tackle the COVID-19 pandemic and mitigate viral transmission, mainland China has implemented various disease prevention measures and arrangements. We hypothesize that these measures may be pose challenges to the management of pediatric asthma. Here, we studied the situation of pediatric asthma in Chengdu during the COVID-19 pandemic and compared the pediatric asthma situation before so as to provide a reference for designing effective management plan for pediatric asthma patients in the future facing the outbreak of epidemic.

An observational study was done to compare the pediatric asthma situation in Chengdu from 2017 to 2019 to the situation under COVID-19 pandemic. Asthma incidence, severe asthma attack, air quality, temperature, and patient follow-up were examined.

The number of monthly asthma cases decreased significantly in February 2020. The number of asthma cases in 2017-2019 positively correlated with levels of particulate matter PM 2.5 (p = 0.006) and PM10 (p = 0.005), while it negatively correlated with temperature (p = 0.048). No correlation was identified in 2020. A higher rate of severe asthma attack cases (9.69%) was observed among asthma patients in 2020 (p = 0.014). Differences were identified between the monthly severe asthma attack during the period 2017-2020 (p<0.001). The rate of severe asthma attack cases peaked in June and September 2020. The percentage of patients who failed to undergo pulmonary function tests was 34.5% in 2020, remarkably higher than in the previous 3 years (p<0.001).

The situation and management of pediatric asthma during the 2020 COVID-19 pandemic differed from those in previous years, with more emphasis placed on disease prevention practices and facilities. To design future pediatric asthma management practice, the environmental and psychological impact on asthma management should also be considered. Local areas should make good use of telemedicine to manage pediatric asthma effectively.

YAP Promotes Cell Proliferation and Epithelium-Derived Cytokine Expression via NF-κB Pathway in Nasal Polyps.

Journal of Asthma and Allergy

Hippo-Yes-associated protein (YAP) pathway plays an important role in epithelial cell proliferation and inflammation development in chronic rhinosinusitis with nasal polyps (CRSwNP). However, the underlying mechanisms remain unclear.

This study intends to investigate the role of YAP and the nuclear factor kappa-B (NF-κB) pathway in cell proliferation and the expression of epithelium-derived cytokines in nasal polyps (NP).

The expression levels of YAP, TEA domain family member 1 (TEAD1), Ki-67, and NF-κB as well as interleukin (IL-) 33, IL-25 and thymic stromal lymphopoietin (TSLP) in sinonasal mucosa, primary nasal epithelial cells (NPECs), and human nasal epithelial RPMI 2650 cells were detected. NPECs were cultured and treated with verteporfin (VP), YAP shRNA or BAY 11-7082.

The hippo pathway effector YAP, Ki-67, p65 NF-κB, and cyclin D1 were significantly increased in NP compared with control mucosa, which was accompanied by overexpression of IL-33, IL-25, and TSLP. Pharmaceutical inhibition of YAP by VP suppressed cell proliferation of RPMI 2650 cells by blocking cell cycle progression at G0/G1 without inducing obvious cell apoptosis. Furthermore, lentiviral transfection-mediated knockdown of hippo pathway activity reduced the expression of IL-33, IL-25, TSLP as well as p65 NF-κB in RPMI 2650 cells. Downregulation of NF-κB pathway with BAY 11-7082 in NPECs could decrease the mRNA level of TSLP, IL-33 and IL-25 accordingly.

Inhibition of hippo pathway suppressed nasal epithelial cell proliferation and declined the expression of epithelium-derived cytokines via the NF-κB pathway in NPECs.

Immunological effector mechanisms in HIV-1 elite controllers.

Current Opinion in Cell Biology

HIV-1 elite controllers encompass small populations of people infected with HIV-1 who can spontaneously control plasma viral loads below the limit of detection, in the absence of antiretroviral treatment. Antiviral immune responses are likely to contribute to such an impressive HIV-1 disease outcome. In this review, we discuss recent novel findings regarding antiviral innate and adaptive immune responses in elite controllers.

Elite controllers maintain a pool of infected cells in which intact HIV-1 proviruses are more frequently integrated into noncoding regions of the host genome, likely conferring a state of deep latency. This atypical viral reservoir configuration is best explained by potent antiviral immune responses that can successfully eliminate virally infected cells in which proviruses are integrated into permissive chromatin. However, identifying the specific type and nature of this immune selection pressure represents a formidable challenge. Recent studies continue to support the role of HIV-1-specific CD8+ T cells as the main driver of elite immune control of HIV-1, however, increasing evidence suggests that their role is complemented by a fine-tuned interplay with innate immune cell subsets. Therefore, the combination of different immune effector mechanisms may shape antiviral immunity in elite controllers.

Understanding the complex immune mechanisms responsible for natural, drug-free HIV-1 control represents a premier avenue to find and develop interventions for a cure of HIV-1 infection. Future single-cell assays designed to uncover the full genetic, epigenetic, transcriptional and functional complexity of antiviral immune responses in elite controllers may allow us to define correlates of antiviral immune protection in greater detail.

The impact of viraemia on inflammatory biomarkers and CD4+ cell subpopulations in HIV-infected children in sub-Saharan Africa.

AIDS

To determine the impact of virological control on inflammation and cluster of differentiation 4 depletion among HIV-infected children initiating antiretroviral therapy (ART) in sub-Saharan Africa.

In a sub-study of the ARROW trial (ISRCTN24791884), we measured longitudinal HIV viral loads, inflammatory biomarkers (C-reactive protein, tumour necrosis factor alpha, interleukin 6 (IL-6), soluble CD14) and (Uganda only) whole blood immunophenotype by flow cytometry in 311 Zimbabwean and Ugandan children followed for median 3.5 years on first-line ART. We classified each viral load measurement as consistent suppression, blip/post-blip, persistent low-level viral load or rebound. We used multi-level models to estimate rates of increase or decrease in laboratory markers, and Poisson regression to estimate the incidence of clinical events.

Overall, 42% children experienced viral blips, but these had no significant impact on immune reconstitution or inflammation. Persistent detectable viraemia occurred in one-third of children and prevented further immune reconstitution, but had little impact on inflammatory biomarkers. Virological rebound to ≥5000 copies/ml was associated with arrested immune reconstitution, rising IL-6 and increased risk of clinical disease progression.

As viral load testing becomes more available in sub-Saharan Africa, repeat testing algorithms will be required to identify those with virological rebound, who need switching to prevent disease progression, whilst preventing unnecessary second-line regimen initiation in the majority of children with detectable viraemia who remain at low risk of disease progression.

Second-generation mother-to-child HIV transmission in South Africa is characterized by poor outcomes.

AIDS

The worldwide incidence of pregnancy for women living with perinatal HIV infection is increasing. Subsequently, there is growing risk of second-generation mother-to-child HIV transmission. The infant clinical outcomes for such a phenomenon have yet to be described.

Blood results and clinical data were collected in the first 3 years of life. In two cases, sample availability allowed confirmation by phylogenetic analysis of grandmother-to-mother-to-child HIV transmission.

Outcomes were poor in all six cases. All six mothers had difficulty administering twice daily combination antiretroviral therapy to their infants due to difficulties with acceptance, disclosure, poor health and being themselves long-term nonprogressors. Nonnucleoside reverse transcriptase inhibitor-resistant virus was detected in all mothers tested. None of the infants maintained suppression of viraemia on combination antiretroviral therapy. One infant died, and another was lost to follow-up.

As the numbers of second-generation mother-to-child transmissions increase, it is important to highlight that this mother-infant dyad represents an extremely vulnerable group. In order for them to survive and thrive, these infants' mothers require their specific needs to be addressed and given intensive support.